Which 454 Cylinder head to buy, opinions welcome

[alamantia]

I just picked up a 1989 chris craft 245 with a 454 and a Bravo 1 "performance" drive, whatever the heck that is. I never saw the word "performance" on a bravo 1 before but what do I know? Anyway. I got the boat because I couldn't beat the price, but I took a gamble because only the short block resides in the engine compartment. Seems the guy that I bought it from had a "valve noise" so he pulled one head and didn't see an issue, pulled the other head and saw an issues with one of the valves. He dropped the heads off at a local machine shop and forgot about it and the boat sat for 3 years and I picked it up. Now I have this damn thing in my driveway with a short block 454 in it and I have to get it running. I see exhaust manifolds and risers, I see a quadrajet carburetor in a box and I cant tell you what compression the pistons are or the cam specs. I don't have any idea where the intake manifold is. All I can tell is he smeared grease all over the block and inside the cylinder walls and wrapped the motor in plastic. I cant find any rust on this thing. I drained some of the oil and cant find any evidence of water in the block. I am thinking about just buying heads and an intake manifold, crossing my fingers and turning the key to see what weve got.

Since I have to buy heads and a manifold, what heads to get? I know there are peanut port, oval port and rectangular port heads. I see a lot of the 330hp mercs use the peanut ports. I see the 385hp mercs use the rectangular ports. Which to buy? The dry weight of this boat is 5000 lbs and it is 24' long. My assumption is that this thing will plane out around 3000 RPM's and redline around 5000 RPM's so I sort of think I will be looking for heads that preform in the 3000-5000 RPM range.

If the peanut ports are good for low end torque and the rectangular ports are good for high end HP. Wouldn't I want to pick up a set of large oval ports for this engine?

I am open to your suggestions as I am clueless on which heads and manifold I should buy this week. I figured this forum would be a good source of info. I am sure there are plenty of you guys that experimented on these 454's

 

[old bird]

Well, beings no one responded to you I will. I don't really know much, but,
I thought Peanut and Oval where the same heads on the earlier 454's ( Mark IV ) that's whats on mine. I'm not sure about the later models. there are guys on here that really know this stuff, i'm surprised they hadn't chimed in.
Anyway, what does the previous owner say? Any chance the machine shop still has the heads? Where did the Intake go? Get a serial # off the block.
Sorry I'm actually no help, but I did bring it back up,
Good Luck

 

[alamantia]

Yeah seriously. I thought id get some replies. Funny you asked about the machine shop still having them. They do! But they are peanut ports and need to be gone through. he also has the manifold. The cheaper option would be to have them machine them and get them back. But that will take weeks. I am thinking that there are better heads out there i could just buy and have in 2-3 days. I see summit and jegs have large oval port assembled merlin heads for $750ea. i am assuming i have a gen IV block but i am not positive. How do i find out? Casting # or tell tale feature? I would think all BBC heads from any generation would fit, no?

 

[alldodge]

The question I would have is what do you want your boat to do?

Port size has a direct relationship to air flow, more air flow more possibility of building more power. If you want a 300 or 330 HP 454 then no biggy, get the oval port heads. If you want to build around the 400HP or more then we need rectangular ports and a bunch of other things.

I have a 3800 lb Rinker with a 300 HP 454 and it will do 60mph on a good day and all things working. You say your boat weights in at 5K so you will need more if you want to do the same mph.

So far as the term "Bravo 1 performance" drive, that goes along with the auto industry high performance 5.0 motor. In the year of your boat is when Merc was coming out with the new Bravo 1, and to this day it still is the main mover for Merc up thru 500 HP or so. It is a very good drive and can handle everything you probably are willing to pay for

 

[alamantia]

Cool deal. Thanks for the input!

 

[Tail_Gunner]

You have to find the cast number's on the block...if its a 330hp 454 your dead in the water with upgrades now if it is a mag with forged internal's you have a lot of option's.Sounds limiting but the cast block is a weak with a flat tappet cam married to marginal heads.

 

[buzzm19]

on those 454's the number on the block is important although gm was deceiving on those numbers like the (most go by the last 3 digets) the 445 block states two or 4 bolt blocks the 512 blocks were 2 or 4 bolt as an example. The main thing is if it is a 4 bolt main, two bolt mains were the ackilles heel on gm's big block. If you have a 4 bolt main thats the first good and as far as i am concerned the only way to go especially in marine engines (how many cars run in the 4000rpm range for ten to 15 min) get the picture? That boat you have is heavy and you need some good horses to run it properly, I would say around 350- 400 hp range and that is nothing compared to what those motors can produce and still be reliable and live a long life. There is nothing wrong with a hydrolic flat tappet cam and is also very reliable. I love rochester carbs they are also good all around performers but you need some older guys like me who knows them. I wanted a big block boat and blew a good deal but thats water over the dam. I now run a wellcraft 26' nova with twin small blocks 300 hp ea and I can run 55 mph all day long and not hurt anything, and guess what yea rochester carbs. If it was me I would go rectangle port something like the 188 heads. On the last note bbc do not have a problem with low end torque, and your bravo one's will easly handle 500 hp. I hope this is some help Buz

 

[alamantia]

Good info here. The tops of tge pistons say "0.030" so i am guessing they are forged. Im not sure about the rods. These are the heads im looking at. How will these work?http://www.jegs.com/webapp/wcs/stor...10002&langId=-1&productId=86134&storeId=10001

 

[Bondo]

Good info here. The tops of tge pistons say "0.030" so i am guessing they are forged. Im not sure about the rods. These are the heads im looking at. How will these work?http://www.jegs.com/webapp/wcs/stor...10002&langId=-1&productId=86134&storeId=10001

Ayuh,.... That just says the motor has been rebuilt/ over-bored .030"....... They could still be hyper-utectic, or cast pistons,...

 

[buzzm19]

If you don't know or can't get the numbers off the block, you are only asking for trouble. How do you expect to build a motor if you don't know what you have? Buz

 

[Tail_Gunner]

Good info here. The tops of tge pistons say "0.030" so i am guessing they are forged. Im not sure about the rods. These are the heads im looking at. How will these work?http://www.jegs.com/webapp/wcs/store...&storeId=10001

It is important as everyone is to trying to point out to identify the type of BB you have. The 330 hp is setup with peanut heads...low compression and a very small cam to produce big tourqe at low rpm if you add high high flow heads to that combination it will be.....well a real turd so to speak. BB are a bit different than a small block just take some time to do it right you wont be dissapointed if you do.

The 330hp merc is not a mag engine
The 365 Hp version is and generally does not have peanut heads.

What are the casting numbers on the heads they maybe ovals and not peanut's

Peanut head

Ovals

 

[alamantia]

I dont want to buy rectangle ports. I dont want to build a motor. Its not going to go very fast with no heads. All i plan on doing is buying heads tomorrow putting them on and putting it in the water. Since i have no heads i must buy heads. Will the heads in my link work?

 

[sub2010ss]

There's some assumptions being made that whoever did the rebuild replaced with factory replacement parts. Even with the casting numbers, dealing with an engine that has already been gone through, the only way you'll know for sure what components are inside is to tear it apart. With that being said, if you just want it to run, do whatever is cheapest and fastest to get her done.

 

[alamantia]

There's some assumptions being made that whoever did the rebuild replaced with factory replacement parts. Even with the casting numbers, dealing with an engine that has already been gone through, the only way you'll know for sure what components are inside is to tear it apart. With that being said, if you just want it to run, do whatever is cheapest and fastest to get her done.

I agree. I am just not sure how the ones i selected will work. I guess ill just get them and find out for myself.

 

[alldodge]

I dont want to buy rectangle ports. I dont want to build a motor. Its not going to go very fast with no heads. All i plan on doing is buying heads tomorrow putting them on and putting it in the water. Since i have no heads i must buy heads. Will the heads in my link work?

We do not know............ We need to know what you have in order to tell you if they will
Here is a link to locate the engine casting number and it will also tell you what engine you have
http://www.mortec.com/

 

[Tail_Gunner]

http://www.ebay.com/itm/like/161606253999?lpid=82&chn=ps

Something like the above GM 049 oval port heads, run over to offshoreonly and confirm that you might run into a good deal over there.

 

[old bird]

I'd get the shop to go thru the original Peanut heads, get the manifold back, and put it back together and go. You won;t be dissapointed with the Peanut heads.That 330 hp w/big torq will pick up your 5000 lb. Chris Craft and boogie. Your going to spend alot of money on heads and intake manifold and end up with something no better and possible worse. Just my 2cents, but you've got plenty else to spend $ on.

 

[alamantia]

Much apreciated!

 

[alamantia]

The block # is 14015445. The heads i bought are 781 castings with the bigger valves. These are the large oval port heads. the boat is a heavy speed boat. I cant see getting peanut ports just to get it up on plane and have it starve for horse power over 4000RPMs and i cant see buying rectangle ports and struggeling to get it up on plane with a full boat. I figure these large oval ports will be the best of both worlds.

 

[Tail_Gunner]

The block # is 14015445. The heads i bought are 781 castings with the bigger valves. These are the large oval port heads. the boat is a heavy speed boat. I cant see getting peanut ports just to get it up on plane and have it starve for horse power over 4000RPMs and i cant see buying rectangle ports and struggeling to get it up on plane with a full boat. I figure these large oval ports will be the best of both worlds.

If you have a machineist you might want to try and get the compression up to 9......9.5 that would be a much improved engine..not for hotrodding just for low end tourqe and throttle response.